Generally, the customer base of operators of communication networks is, for historical reasons, divided into so-called pre-paid and post-paid customers because the related time scales for processing of charges have been different according to several orders of magnitude.
Pre-paid customers are related to immediate, real-time price calculation, and post-paid customers require a billing, e.g., according to once-a-month scheme. This is the reason why pre-paid business is associated generally with the network division of the operator of the communication network, while the post-paid billing is allocated to the billing department.
However, with the issuance of a Bill-Shock-Prevention law real-time billing now also is a must for post-paid customers.
So far, in pure post-paid billing systems the price determination does not have any real-time requirements, as the billing process is normally initiated once a month. For this reason, post-paid billing systems use batch-oriented processing with files containing hundreds of single call information records. Then, these single call information records are forwarded within a bundle in the charging system and are processed for contract mapping, rating/cost control, so that finally the related billing results may be stored in a database. Here, the billing with aggregated records may be efficient because the process may benefit from inherent scheduling algorithms in alignment with the architecture of the processing system.
To the contrary, real-time billing systems are usually using interrupt-based data communication, as every single billing record must be processed with a certain timeframe. The real-time requirement necessitates the forwarding of every single billing record without any aggregation between different billing records.
Here, existing real-time billing systems burden the computer with a high number of context switches, process re-scheduling processes, cache invalidations, etc., in order to respond to a single billing record as fast as possible. Therefore, a latency-response distribution which is billed up from the response processing times of submitted billing records has a large standard deviation or equivalently is smeared out.
However, when the response time for a billing record exceeds a certain threshold of about 50 to 150 milliseconds, the related service which is to be charged will either be cut or lose priority in the communication network. Such degradation of a service to be billed leads to customer disappointment and finally to a degradation in the revenue of the operator of the communication network.